The problems of investigating the dynamic aspects of a lithogenesis process in the human organism, of studying its intensity, of determining the salt composition in the course of a lithogenesis process are currently being researched. Knowledge in this field makes it possible to prevent the formation of urate calculi, to introduce timely corrections into the lithogenesis process, to prescribe and carry out individual therapeutic treatment for urolithiasis cases.
Known in the prior art are methods for predicting urolithiasis based upon detecting a lithogenesis process, such as, e.g. a prediction method based upon detection of urate salt crystals in freshly discharged urine or in urine analyzed Shortly after urination (Ref. V. Ye. Predtechensky "Guide for Clinical Laboratory Investigations", 1964 Medicina Publishers, pp. 420-446), or a method for predicting urolithiasis (SU, A, 1 629 846) based upon evaluation of the crystal-forming activity of urine by mixing solutions of calcium chloride, sodium oxalate and urine, followed by holding the resultant mixture and then counting the number of crystals formed.
However, the above-cited methods are aimed only at detecting a lithogenesis process, and they do not allow the determination to be made as to the extent of this process intensity.
Equally known in the prior art is a method for predicting urolithiasis, in which it is recommended to evaluate the extent of risk of calcium phosphate crystallization in urine by counting the number of crystals thus-formed and having a specific size using recommended mathematical procedures (refer, please, to the "Urological Research", No. 2, 15, 1987, Springer-Verlag, H.-G. Tiselius, "Measurement of the Risk of Calcium Phosphate Crystallization in Urine", pp. 79-81). The latter methods calls for sophisticated mathematical calculations, and its only purpose is to detect the fact of a lithogenesis process.
Also known in the prior art is a method for predicting of urolithiasis (PCT/SU 91/00140), by preparing a protein solution, e.g. albumin solution is added to a urine sample, the resultant mixture is subjected to drying and, if a 100%-crystallization of the urine sample takes place, a urolithiasis case is predicted. The latter method is also aimed at revealing a lithogenesis process, and it cannot be used for evaluating the extent of intensity of a lithogenesis process.
Moreover, there are known in the prior art methods for determining the composition of urate salts participating in urolithiasis (V. Ye. Predtechensky "Guide for Clinical Laboratory Investigations", 1964 Medicina Publishers, Moscow, pp. 452-454; Wandt M., Underhill L. "Brit. J. Urol.", 1988 61 No. 6 478-481; Schubert G., Brien G., Adam K. "Z. Klin. Med.", 1989, 44, No. 11 , 923-928; Nichino T., Sakura T., Sato T., Koiso K., Kaneko S. "Jap. J. Nephrol.", 1987, 29, No. 5, 571-575). All of the above-cited methods are based upon study of the urine constituents (salt deposit, sand, concretions) by the physico-chemical route using adsorption, ion exchange, such as, e.g. chromatography, using X-ray structural analysis, X-ray spectral analysis, thermal analysis involving study of nuclear magnetic resonance, electron para-magnetic resonance and other spin effects.
All of the above-cited methods are suitable only for study of already formed calculi discharged from the human body, and they unable to determine the chemical nature of nascent calculi at early urolithiasis stages, and that of calculi already fully formed, but not withdrawn from the body.
There exists in the prior art no method for determining the chemical composition of calculi-forming urate salts at early urolithiasis stages, or for determining that of calculi fully formed, but not discharged from the organism.